The newly added consent check from https://chromium-review.googlesource.com/c/chromium/src/+/783707 seems to be causing DCHECK crashes.
[7290:7290:1129/095826.261439:INFO:signin_screen_handler.cc(1386)] Login WebUI >> active: 1, source: account-picker
[7290:7290:1129/095827.217329:VERBOSE1:signin_screen_handler.cc(1340)] Login WebUI >> loginVisible, src: oobe, webui_visible_: 0
[7290:7290:1129/095827.219079:VERBOSE1:login_display_host_webui.cc(937)] Login WebUI >> WEBUI_VISIBLE
[7290:7290:1129/095827.219170:VERBOSE1:webui_login_view.cc(630)] Login WebUI >> not emitting signal, hidden: 0
[7290:7290:1129/095829.036305:INFO:signin_screen_handler.cc(1286)] Login WebUI >> AccountPickerReady
[7290:7290:1129/095829.037999:VERBOSE1:gaia_screen_handler.cc(270)] MaybePreloadAuthExtension
[7290:7290:1129/095829.038186:VERBOSE1:gaia_screen_handler.cc(954)] LoadAuthExtension, force: 1, offline: 0
[7290:7290:1129/095829.038530:VERBOSE1:signin_screen_handler.cc(1340)] Login WebUI >> loginVisible, src: account-picker, webui_visible_: 1
[7290:7290:1129/095829.039953:FATAL:thread_restrictions.cc(29)] Check failed: !g_blocking_disallowed.Get().Get(). Function marked as blocking was called from a scope that disallows blocking! If this task is running inside the TaskScheduler, it needs to have MayBlock() in its TaskTraits. Otherwise, consider making this blocking work asynchronous or, as a last resort, you may use ScopedAllowBlocking in a narrow scope.
#0 0x581d60471688 base::debug::StackTrace::StackTrace()
#1 0x581d6046fb9c base::debug::StackTrace::StackTrace()
#2 0x581d604d9c4a logging::LogMessage::~LogMessage()
#3 0x581d6063b137 base::AssertBlockingAllowed()
#4 0x581d604bba14 base::DirectoryExists()
#5 0x581d5f71ba8d GoogleUpdateSettings::GetCollectStatsConsent()
#6 0x581d68e3f066 chromeos::GaiaScreenHandler::LoadGaiaWithVersion()
#7 0x581d5885bb6f _ZN4base8internal13FunctorTraitsIMN5media12PipelineImplEFvRKNS2_15TextTrackConfigERKNS_17RepeatingCallbackIFvNSt3__110unique_ptrINS2_9TextTrackENS8_14default_deleteISA_EEEEEEEEvE6InvokeIRKNS_7WeakPtrIS3_EEJS6_SH_EEEvSJ_OT_DpOT0_
#8 0x581d68e59195 _ZN4base8internal12InvokeHelperILb1EvE8MakeItSoIRKMN8chromeos17GaiaScreenHandlerEFvRKNS5_11GaiaContextERKNSt3__112basic_stringIcNS9_11char_traitsIcEENS9_9allocatorIcEEEEERKNS_7WeakPtrIS5_EEJS8_SH_EEEvOT_OT0_DpOT1_
#9 0x581d68e590fd _ZN4base8internal7InvokerINS0_9BindStateIMN8chromeos17GaiaScreenHandlerEFvRKNS4_11GaiaContextERKNSt3__112basic_stringIcNS8_11char_traitsIcEENS8_9allocatorIcEEEEEJNS_7WeakPtrIS4_EES5_EEEFvSG_EE7RunImplIRKSI_RKNS8_5tupleIJSK_S5_EEEJLm0ELm1EEEEvOT_OT0_NS8_16integer_sequenceImJXspT1_EEEESG_
#10 0x581d68e59004 _ZN4base8internal7InvokerINS0_9BindStateIMN8chromeos17GaiaScreenHandlerEFvRKNS4_11GaiaContextERKNSt3__112basic_stringIcNS8_11char_traitsIcEENS8_9allocatorIcEEEEEJNS_7WeakPtrIS4_EES5_EEEFvSG_EE3RunEPNS0_13BindStateBaseESG_
#11 0x581d585731fc _ZNO4base12OnceCallbackIFvRKN13safe_browsing22ArchiveAnalyzerResultsEEE3RunES4_
#12 0x581d5a8225f5 base::internal::ReplyAdapter<>()
#13 0x581d58b00c2e _ZN4base8internal13FunctorTraitsIPFvNS_12OnceCallbackIFNSt3__110unique_ptrINS_5ValueENS3_14default_deleteIS5_EEEEvEEEPS8_EvE6InvokeIJSA_SB_EEEvSD_DpOT_
#14 0x581d58b07f30 _ZN4base8internal12InvokeHelperILb0EvE8MakeItSoIPFvNS_12OnceCallbackIFvbEEEPbEJS6_S7_EEEvOT_DpOT0_
#15 0x581d5a822bcf _ZN4base8internal7InvokerINS0_9BindStateIPFvNS_12OnceCallbackIFvRKNSt3__112basic_stringIcNS4_11char_traitsIcEENS4_9allocatorIcEEEEEEEPSA_EJSE_NS0_12OwnedWrapperISA_EEEEEFvvEE7RunImplISH_NS4_5tupleIJSE_SJ_EEEJLm0ELm1EEEEvOT_OT0_NS4_16integer_sequenceImJXspT1_EEEE
#16 0x581d5a822ad9 _ZN4base8internal7InvokerINS0_9BindStateIPFvNS_12OnceCallbackIFvRKNSt3__112basic_stringIcNS4_11char_traitsIcEENS4_9allocatorIcEEEEEEEPSA_EJSE_NS0_12OwnedWrapperISA_EEEEEFvvEE7RunOnceEPNS0_13BindStateBaseE
#17 0x581d585de22c _ZNO4base12OnceCallbackIFvvEE3RunEv
#18 0x581d6061c083 base::(anonymous namespace)::PostTaskAndReplyRelay::RunReplyAndSelfDestruct()
#19 0x581d6061c30d _ZN4base8internal13FunctorTraitsIMNS_12_GLOBAL__N_121PostTaskAndReplyRelayEFvvEvE6InvokeIPS3_JEEEvS5_OT_DpOT0_
#20 0x581d6061c254 _ZN4base8internal12InvokeHelperILb0EvE8MakeItSoIMNS_12_GLOBAL__N_121PostTaskAndReplyRelayEFvvEJPS5_EEEvOT_DpOT0_
#21 0x581d6061c1e2 _ZN4base8internal7InvokerINS0_9BindStateIMNS_12_GLOBAL__N_121PostTaskAndReplyRelayEFvvEJNS0_17UnretainedWrapperIS4_EEEEEFvvEE7RunImplIS6_NSt3__15tupleIJS8_EEEJLm0EEEEvOT_OT0_NSD_16integer_sequenceImJXspT1_EEEE
#22 0x581d6061c129 _ZN4base8internal7InvokerINS0_9BindStateIMNS_12_GLOBAL__N_121PostTaskAndReplyRelayEFvvEJNS0_17UnretainedWrapperIS4_EEEEEFvvEE7RunOnceEPNS0_13BindStateBaseE
#23 0x581d585de22c _ZNO4base12OnceCallbackIFvvEE3RunEv
#24 0x581d60475290 base::debug::TaskAnnotator::RunTask()
#25 0x581d60705195 base::internal::IncomingTaskQueue::RunTask()
#26 0x581d604f4a8a base::MessageLoop::RunTask()
#27 0x581d604f4d46 base::MessageLoop::DeferOrRunPendingTask()
#28 0x581d604f5078 base::MessageLoop::DoWork()
#29 0x581d604f9660 base::MessagePumpLibevent::Run()
#30 0x581d604f422c base::MessageLoop::Run()
#31 0x581d60588e8b base::RunLoop::Run()
#32 0x581d5f67818d ChromeBrowserMainParts::MainMessageLoopRun()
#33 0x581d5a7b56c4 content::BrowserMainLoop::RunMainMessageLoopParts()
#34 0x581d5a7c2768 content::BrowserMainRunnerImpl::Run()
#35 0x581d5a7a7b64 content::BrowserMain()
#36 0x581d5f623206 content::RunNamedProcessTypeMain()
#37 0x581d5f626be6 content::ContentMainRunnerImpl::Run()
#38 0x581d5f61ba95 content::ContentServiceManagerMainDelegate::RunEmbedderProcess()
#39 0x581d5f64d3ec service_manager::Main()
#40 0x581d5f621fdf content::ContentMain()
#41 0x581d584193f0 ChromeMain
#42 0x581d584181a2 main
#43 0x7c2fd501a736 __libc_start_main
#44 0x581d58418049 _start
Comment 1 by vsu...@chromium.org
, Jan 16 2018